Akalkuliya is the generalizing concept including various violations of understanding of numbers and commission of arithmetic actions. The number, the numerical category, impossibility to consistently carry out calculations is shown by visual/acoustical not recognition of figures, misunderstanding of a concept. It is diagnosed on the basis of clinical features, results of neurologic, psychiatric survey, arithmetic testing, a cerebral tomography. Treatment is carried out concerning a basic disease, rehabilitation includes special classes in restoration of arithmetic abilities.
Existence of the special center of the account in a brain of the person was described at the beginning of the 19th century. At first physicians assumed that it is located in a frontal lobe, then determined its localization on a joint by a parietal and occipital share of a prepotent hemisphere. In 1926 the German physiologist Hans Berger offered the term "primary akalkuliya" for designation of the frustration of the account caused by direct defeat of the calculating center for difference of pathology from the secondary violations which are observed owing to other cortical dysfunctions. Violations of the account at children have partial character, often are result of an underdevelopment of cognitive abilities therefore in practical neurology are designated by the term "diskalkuliya".
Various forms of pathology are connected with defeat of bark of parietal, occipital, temporal, frontal lobes of a brain. The main etiofaktor leading to pathological changes of cerebral bark are:
- Tserebrovaskulyarny pathology. Akalkuliya can arise at sharp violation of a cerebral blood-groove (an ischemic, hemorrhagic stroke), at the chronic ischemia of a brain leading to gradually accruing vascular dementia.
- Craniocereberal injuries. Disorders of accounting are connected with the brain bruise which is followed by formation of hematomas, sites of a razmozzheniye of brain substance with involvement of areas of bark which participate in process of the account.
- Neuroinfections. Along with other cognitive violations the akalkuliya accompanies encephalitis, meningoentsefalita, encephalomyelitis, variable on an etiology.
- Intoxications. Defeats of brain bark are possible at the sharp poisonings, chronic intoxications including caused by dismetabolichesky processes (a hyperglycemia, uraemia).
- Brain tumors. Lead konveksitalny new growths to loss of cortical functions (a glioma, a meningioma), the intracerebral tumors sprouting or squeezing bark.
- Degenerate diseases of TsNS: Kreyttsfeldta-Jacob's disease, leykodistrofiya, Alzheimer's disease. Akalkuliya is caused by the progressing atrophy of cerebral bark.
Akalkuliya of children's age is more often connected with anomalies of development of a brain, perinatal pathology (a fruit hypoxia, a pre-natal infection, an intra cranial patrimonial trauma), hereditary diseases and dismetabolichesky syndromes.
The account represents difficult multilevel function of higher nervous activity of the person. The center of the account is closely connected with other zones of bark without which participation its full functioning is impossible. Visual "recognition" of figures happens thanks to work of visual area of bark of an occipital share, acoustical — thanks to functioning of the acoustical center of bark which is localized in the top temporal crinkle. Recognition of figures, commission of calculations is carried out with the participation of memory, demands a certain concentration of attention. The solution of the simplest mathematical tasks happens under control of the frontal departments of bark which are responsible for ability to perceive abstract concepts, to carry out purposeful activity.
Etiologichesky factors start the diffusion or local vascular, inflammatory, post-traumatic, dystrophic processes in structures of brain bark leading to a degeneration and death of neurons. Akalkuliya arises when the cortical zones participating in realization of function of the account are involved in pathological process. Defeat of the center of the account extremely seldom has the isolated character, is in most cases combined with other violations of the cognitive sphere.
Taking into account the emergence mechanism the akalkuliya is classified on two main forms: primary and secondary. Primary (specific) akalkuliya is caused by pathological processes in the field of the calculating center on a joint of an occipital and parietal share of the dominating hemisphere. The secondary (nonspecific) akalkuliya arises at defeat of the other zones of bark participating in difficult process of the account happens four types:
- Optical — violation of visual perception of figures. Develops at pathology of occipital areas of cerebral bark. Accompanies visual agnosia.
- Touch (acoustical) — is caused by disorder of recognition of sounds and speeches. It is connected with defeat of the top temporal crinkle, it is combined with touch aphasia.
- Akustiko-mnestichesky (amnestichesky) — violations is the cornerstone disorder of slukhorechevy memory at pathological processes in temporal departments of bark. Is followed by other violations of memory.
- Frontal — operations with figures are impossible because of frustration of the organization and control of purposeful activity (praksis). Other displays of apraxia are observed.
Clinical manifestations vary depending on a pathology form. Primary akalkuliya is characterized by lack of understanding of a concept number, numerical categories (for example, patients do not see a difference between numbers 152 and 125), impossibility of comparison of numbers, carrying out the elementary arithmetic calculations. It is combined with the spatial agnosia which is shown violation of orientation "right-left", "top bottom", perceptions of system of coordinates, etc. arising at defeat of parietal area.
The secondary akalkuliya comes to light in combination with other frustration of the cognitive sphere: agnosia, apraxia, aphasia, amnesia. The optical form is shown by absence or errors of recognition of the represented numbers. Patients cannot call the seen number, confuse figures, similar in the drawing (7 and 1, 9 and 6). The concept of number, perception of numbers aurally, ability to make calculating operations in mind is kept. The symptomatology of visual agnosia — not recognition of letters, persons, images of objects is typical. The dysgraphia, a dyslexia is noted.
The touch akalkuliya accompanies acoustical agnosia — violation of recognition of sounds, speech elements. Patients do not understand heard, say much, with shift of syllables, repetitions, mistakes. Reading numbers, understanding of the read arithmetic calculations suffer to a lesser extent. The Akustiko-mnestichesky form is connected with the frustration of volume of perception of numbers, images representations complicated by a number recall according to the name. Increase in number of errors of writing of figures is characteristic from dictation at increase in speed of their giving, large volume of a task, the raised zashumlyonnost. The account is complicated, a concept of number, categories, structures of the account of a sokhranna.
The frontal akalkuliya is shown in structure of apraxia. Violation concerns the sequence of performance of mathematical calculations along with disorder of activity at the solution of any objectives. The patient owns the automated account within ten, understanding of prime numbers, the multiplication table, but cannot operate with multidigit numbers, make number on the offered figures, find structure of number, solve an example with prime numbers in several actions. Changes of the psychoemotional sphere are noted: impulsiveness, lability, stereotype, aggression, the broken behavior.
As the akalkuliya is a part of complex violations of the cognitive sphere, its exarticulation among leading intellectual frustration represents a certain diagnostic complexity. One more task is definition of a form of pathology, diagnosis of a basic disease which manifestation was an akalkuliya. The following diagnostic techniques are used:
- Collecting anamnesis. Allows to find out how the disease began and developed, than it was provoked.
- Research of the neurologic status. Survey of the neurologist gives the chance to reveal focal symptomatology, to assume localization of cerebral defeat. At children inspection includes assessment of level of mental development. Patients with ChMT, intrakranialny tumors in addition consult the neurosurgeon.
- Survey of the psychiatrist. It is necessary for patients with violations of the mental sphere, helps to differentiate cognitive frustration from mental diseases.
- Arithmetic testing. It is directed to diagnostics of a form of an akalkuliya. Includes a research of visual, acoustical understanding of figures, abilities to remember numbers, to make calculations.
- MRT, brain MSKT. Neurovisualization reveals morphological changes, characteristic of a basic disease: post-traumatic hematomas, intracerebral tumors, inflammation centers, stroke zone, degenerate processes. In case of tserebrovaskulyarny pathology UZDG, MRT of vessels of a brain is appointed.
Treatment of an akalkuliya
Therapy is directed to knocking over of etiopatogenetichesky mechanisms of the main disease, the subsequent restoration of the lost neurologic functions, including ability to operate with numbers. Treatment is carried out step by step.
Medicamentous therapy of a basic disease:
- Correction of cerebral haemo dynamics. At intrakranialny hemorrhages antifibrinolitik (gamma aminocaproic acid), vasoprotectives (calcium medicines, sodium etamsylate) are applied, at cerebral ischemia — vasodilating (), the means improving microcirculation (), trombolitik ().
- Neurometabolic therapy. In various volume it is carried out practically at any cerebral defeats. Includes nootropa, amino acids, antioxidants, the combined means.
- Prevention of hypostasis of a brain. Diuretic pharmaceuticals are appointed, at threat of hypostasis drop introduction of osmodiuretik is carried out.
- Psychotropic drugs. Sedative, tranquilizers, neuroleptics are applied according to indications to knocking over of psychomotor excitement, emotional lability, aggression.
- Etiotropny therapy of infections. It is required to patients with infectious damage of a brain, it is made according to the established activator nature (bacterial, virus, parasitic).
- Arithmetic occupations. Have to correspond to structure of the revealed violations completely. Various techniques include use of cards with figures, restoration of ideas of numerical categories, pronunciation of numbers, performance of arithmetic actions.
- Psychotherapy. The psychotherapeutic help is necessary for correction of the relation of the patient to the arisen problems of the intellectual sphere, formation of a positive spirit on rehabilitation occupations.
- Logopedic occupations. Are shown at acoustical agnosia. Are carried out by the logopedist within correction of aphasia.
In case of sharp process (a stroke, encephalitis, ChMT) the pharmacotherapy is carried out in the beginning, rehabilitation is carried out after knocking over of a sharp state. At the chronic course of the main pathology (chronic cerebral ischemia, degenerate defeats of TsNS) medicamentous therapy is combined with recovery. Radical neurosurgical treatment is shown to patients with intra cranial new growths.
Forecast and prevention
Akalkuliya is a separate symptom in structure of basic pathology of a brain, its forecast is continuously connected with character and the course of the main disease. Correct therapy, young age of the patient provide to 100% recovering of function of the account from the postponed trauma, encephalitis, sharp intoxication, a lacunary stroke. The resistant akalkuliya negatively affects quality of life of the patient, worsens his social adaptation. Predictively adverse factors are cerebral anomalies, advanced age, extensiveness of a zone of defeat, impossibility of radical removal of tumoral process, steady progressing of degenerate pathology. Prevention comes down to the prevention of ChMT, infectious diseases, perinatal pathology, toxic defeats, to timely treatment of tserebrovaskulyarny diseases.